A. Field of the Invention
The invention relates in general to an apparatus for providing interconnectivity to a stack of network devices, and particularly to a small form-factor pluggable linking apparatus for use in stackable network switches.
B. Description of the Related Art
It is known in the art that Ethernet bandwidth can be expanded via the stacking of switches. Switches in a stack configuration are connected in a cascade utilizing stacking modules. For expansion, a conventional stackable switch provides an open slot for installation of stacking modules, which is equipped with a stacking port and a GBIC (Gigabit Interface Converter) port. While the stacking port is for switch stacking, the GBIC port provides for flexible deployment of multimode or extended cable-length single mode fiber.
As the Ethernet speed increases to a gigabit per second, 100BaseT GBIC has been widely adopted for fiber environments. A stackable switch is usually packed with 100BaseFX multimode fiber ports and GBIC-based Gigabit Ethernet ports in a rack unit stackable form factor. Since the speed is increased 10 times, the speed of port for interconnection also needs to be increased comparably to reduce port latency.
GBIC, currently at revision 5.5 by the Small Form Factor (SFF) Committee, has evolved from copper to optical fiber transmission (Module Definition xe2x80x9c7xe2x80x9d) and become widely used. One of its popular applications is for stacking expansion of switches in gigabit Ethernet systems. For example, GigaStack(copyright) GBIC shown in FIG. 1, manufactured by Cisco systems, Inc. of San Jose, Calif., is one linking apparatus used for stacking gigabit Ethernet switches. However, it takes up considerable panel surface area in comparison to miniature GBIC standard. This is due to its relatively large slot opening that limits the number and placement arrangement of networking slots on the back plane of a switch device.
The present invention provides an improved compact linking apparatus for use in network devices to increase system port density. The one-piece linking apparatus of the invention provides a simple, efficient, and very cost-effective compact linking apparatus for coupling USB (Universal Serial Bus) cables in stacking switches.
Moreover, the linking apparatus of the invention attains the flexibility and simplicity of the USB connector in connector design and ease of use. Also, the linking apparatus is hot-swappable and compliant with miniature GBIC standard for plugging into a miniature GBIC port of a stackable switch.
The present invention achieves the above and other objects by providing a linking apparatus for use in a cascade stack of stackable network devices. The invention includes an electronic circuit configured for providing stacking interconnection among the network devices. A miniature GBIC-compliant connector is at an end of the electronic circuit. Two USB (Universal Serial Bus) connectors arranged as a stacking module is at the other end of the electronic circuit.